dumb down

Collins Concise English Dictionary © HarperCollins Publishers::

dumb down verb

1. (transitive) to make or become less intellectually demanding or sophisticated: attempts to dumb down news coverage

WordReference Random House Learner's Dictionary of American English © 2025

dumb /dʌm/   adj., -er, -est. 

1. lacking intelligence or good judgment;
   stupid;
   dull-witted:
   He was dumb to try a stunt like that.
2. stupid;
   silly;
   useless:
   What a dumb idea!
3. lacking the power of speech (often considered offensive when applied to humans):
   a dumb animal.
4. temporarily unable to speak:
   We were all dumb with astonishment at his outrageous comments.
5. refraining from any or much speech;
   silent:
   I kept dumb.
6. made, experienced, etc., without speech:
   in a dumb, furious rage.
7. Computing lacking electronic processing power of its own:
   a dumb computer terminal.

dumb•ly, adv. 
dumb•ness, n. [uncountable]

WordReference Random House Unabridged Dictionary of American English © 2025

dumb  (dum), adj., -er, -est, v. 

1. lacking intelligence or good judgment;
   stupid;
   dull-witted.
2. lacking the power of speech (often offensive when applied to humans):
   a dumb animal.
3. temporarily unable to speak:
   dumb with astonishment.
4. refraining from any or much speech;
   silent.
5. made, done, etc., without speech.
6. lacking some usual property, characteristic, etc.
7. Show Business performed in pantomime;
   mimed.
8. Computing pertaining to the inability to do processing locally:
   A dumb terminal can input, output, and display data, but cannot process it.
   Cf. intelligent (def. 4).
9. [Naut.]
   • Naval Terms (of a barge) without means of propulsion.
   • Naval Terms (of any craft) without means of propulsion, steering, or signaling.

v. 

10. dumb down, to revise to appeal or be understandable to less intelligent people;
    lower the intellectual content of:
    to dumb down a textbook; the dumbing down of American movies.

• bef. 1000; Old English; cognate with Old Norse dumbr, Gothic dumbs, Old Saxon dumb, Old High German tump, German dumm

dumb′ly, adv. 
dumb′ness, n. 
Synonyms

• 2, 3. Dumb, mute, speechless, voiceless describe a condition in which speech is absent.
  Dumb was formerly used to refer to persons unable to speak; it is now used almost entirely of the inability of animals to speak:
  dumb beasts of the field.
  The term mute is applied to persons who, usually because of congenital deafness, have never learned to talk:
  With training most mutes learn to speak well enough to be understood.
  Either of the foregoing terms or speechless may describe a temporary inability to speak, caused by emotion, etc.:
  dumb with amazement; mute with terror; left speechless by surprise.
  Voiceless means literally having no voice, either from natural causes or from injury:
  Turtles are voiceless. A laryngectomy leaves a person voiceless until he or she has learned esophageal speech.

dumb, +v. 

1. dumb down, to revise to appeal or be understandable to less intelligent persons;
   lower the intellectual content of:
   to dumb down a textbook; the dumbing down of American movies.